1. Field of the Invention
Embodiments of the invention relate to a high pressure device for fluid media.
In particular, embodiments are directed to a cylinder unit of a high pressure pump for a fluid with a pressure of greater than 2,000 bars. The cylinder unit includes a cylinder formed by shrink connection of at least two concentric, tubular components, and the cylinder unit is detachably connected on one side to a flange part with a sealing system, in which a plunger is axially moveable back and forth, and is connected on another side to a valve body.
2. Discussion of Background Information
Components of high pressure devices, in particular a wall of a cylinder of high pressure pumps, are exposed during operation to considerable tensile stresses, which are possibly of an unsteady nature or act in a pulsating manner, due to an internal pressure of over 2,000 bars.
The tensile stresses can thereby approach the yielding point of the materials in sections of the cylinder wall, but at least cause a long-duration flow of the material, which is constantly diminished in a logarithmic tempo at a given tension.
It is known to a person skilled in the art to provide tubular component parts with concentric, thermally shrunk-on parts for high internal pressures or to reinforce fluid-conducting pipes with shrunk-on outer components or outer pipes.
Via pipe body of this type formed by a shrinking method from multiple concentric components, it is possible to embody the tensions in the parts of the pipe wall for a high pressure operation such that the most uniform material stresses possible occur over the cross section or that the tensile stress concentrations in the part, which could cause a plastic deformation of the material, are avoided.
Cylinder units or pipe bodies made from a compound of at least two components formed by a shrinking-on of an outer part have however among other things a disadvantage, namely that the inner component in the pipe compound can be axially moved and/or stretched under pulsating or possibly alternating stress. This can, in the flange region of the plunger device and/or in the valve body connection region, lead to problems in the system of a sealing of the high pressure fluid.